Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Income Statement [Abstract]
Revenue	$ 28,510,000	$ 35,606,000
Cost of goods sold	13,378,000	12,407,000
Gross profit	15,132,000	23,199,000
Operating expenses:
Research and development	3,536,000	4,787,000
Clinical and regulatory affairs	3,165,000	3,785,000
Marketing and sales	14,496,000	16,786,000
General and administrative	10,119,000	9,416,000
Restructuring costs	0	419,000
Total operating expenses	31,316,000	35,193,000
Loss from operations	(16,184,000)	(11,994,000)
Other income (expense):
Interest expense	(10,527,000)	(8,490,000)
Other income (expense), net	(1,122,000)	318,000
Change in fair value of contingent consideration related to acquisition	300,000	200,000
Change in fair value of derivative liabilities	10,175,000	(2,023,000.000)
Loss on debt extinguishment	(730,000)	0
Total other expense, net	(1,904,000)	(9,995,000)
Net loss before income taxes	(18,088,000)	(21,989,000)
Income tax expense	(28,000)	(39,000)
Net loss	(18,116,000)	(22,028,000)
Comprehensive loss, net of taxes:
Net loss	(18,116,000)	(22,028,000)
Other comprehensive income (loss) foreign currency translation	748,000	(598,000)
Comprehensive loss	$ (17,368,000)	$ (22,626,000)
Basic and diluted net loss per share (in dollars per share)	$ (0.90)	$ (2.12)
Shares used in computing basic and diluted net loss per share (in shares)	20,067	10,374